Heating but no hot water

[MikeB2003]

Hi experts,

i'm looking for some advice to get to the bottom of my boiler problem.

The boiler is a Glowworm Ultimate 40FF so a traditional NOT combi boiler.

The problem is i cant get hot water.

• Call for heating alone and boiler comes on and heats up the rads.
• Call for hot water alone and the boiler does nothing.
• Call for both and the boiler does nothing
• If the boiler is on because heating alone is called for and you then call for hot water too the boiler switches off.

My first thought was to change the motorised valve. Done (body and electric top part) and same issue
After this i thought it had to be electrical so the PCB. Changed and same issue.

Currently to get a tank of hot water i have to remove the motorised valve and manually move the 3 port valve. Then turn the boiler on to heating.

Any help would be welcome.

Thanks
Mike

 

[Basher]

When you ask for hot water, power to activate the boiler should be coming via the cylinder stat.
Is the cylinder stat hard wired, or is it an rf link? (If the latter - batteries OK? Paired etc?)
Is the stat working and set at the correct temperature?

When you call for both rads and HW, the 3-port moves to the middle, the end microswitch in the 3-port that powers the boiler will open and and remove power from the boiler.
So what you describe makes sense if the cylinder stat is not providing power.

May require diagnosing with a multimeter etc?

 

[MikeB2003]

When you ask for hot water, power to activate the boiler should be coming via the cylinder stat.
Is the cylinder stat hard wired, or is it an rf link? (If the latter - batteries OK? Paired etc?)
Is the stat working and set at the correct temperature?

When you call for both rads and HW, the 3-port moves to the middle, the end microswitch in the 3-port that powers the boiler will open and and remove power from the boiler.
So what you describe makes sense if the cylinder stat is not providing power.

May require diagnosing with a multimeter etc?

Hi Basher,

Thanks for replying.

I have just checked the (hard wired) cylinder stat and I get zero volts with hot water turned on the boiler.

When I turn off the hot water 240v is on the out side of the stat (so going to the motorized valve).

Any ideas? It seems the boiler isn't sending the power to the stat.....

Thanks in advance for any advice.

Mike

 

[ShaunCorbs]

Remove prog / timer and link out eg give live to the hot water on at the stat does it work if yes prog / timer gone

Be careful as your working around / with live parts

 

[MikeB2003]

Remove prog / timer and link out eg give live to the hot water on at the stat does it work if yes prog / timer gone

Be careful as your working around / with live parts

Hi ShaunCorbs,

Fault found!

As I started to remove the programer I noticed how loose/unsecure it was.

I decided to try to push it together while moving the switch and the boiler sparked to life.

Thanks for the help
Mike

 

[Basher]

Sorry missed previous posts - glad you found the problem!